This project is a study of the solution chemistry, liquid-solid equilibria and the kinetics of approach to equilibrium of the major components of urinary stones, calcium oxalate, uric acid, magnesium ammonium phosphate and calcium phosphate. The studies will utilize ion equilibrium computation, solubility measurements, measurement of adsorption at the liquid-solid interface, measurement of binding of small molecules by macromolecules measurement of zeta potential and measurement of crystal growth and aggregation as the primary experimental techniques. Stability constants, solubility constants adsorption parameters, and crystal growth and aggregation rates that will be derived from the studies will be applied to evaluation of possible mechanisms of urolithiasis and will also be used in further experimental studies of the disease urolithiasis. Results obtained from this project will also have direct bearing and application on the physical chemical aspects of the disease gout. This project is an integral part of a long-term program of study on urolithiasis.